. Today Israeli defense forces escalated the battle with hamas, moving from the air to the ground in gaza. ABC's Alex Marquardt is on the scene. Alex? Good morning, Dan. The sun is coming up here in gaza and with it many questions about the size of the operations Israel is planning on carrying out here in gaza in the coming days and possibly longer. Overnight, Israeli forces fired flares into the skies above gaza as they pummelled the strip with artillery, before Benjamin nen a annihue said he was escalating. The goal to take out the network of tunnels that have been built by hamas and used, Israel says, to carry out attacks. So in that respect, so far it's a relatively limited separation, but netanyahu says it could be expanded. His government has called up 18,000 more reserve troops, bringing the total to now more than 60,000. There had been a window of hope yesterday when for five hours, Israel and hamas agreed to a pause in the fighting for humanitarian reasons. Israel accused hamas of violating that peace, and as soon as the time limit expired, the two sides resumed firing. So far, 250 Palestinians have been killed in air strikes by Israel. One Israeli man also killed by a Palestinian mortar. There is no time frame on this Israeli operation. The government says it will continue as long as it takes to stop the rockets from being fired at Israel and to strike a blow against hamas's infrastructure. For its part, hamas now warning that Israel will pay a high price for this ground incursion. Over the past few days, there had been hopes that Egypt would be able to mediate a ceasefire between hamas and Israel, but those hopes, at least for now, have been dashed. Dan? All right, thanks, Alex. Just now, we are learning that an Israeli soldier has been killed in action, according to Israeli defense forces.

This transcript has been automatically generated and may not be 100% accurate.